Patent Document 1, for example, discloses an electric power tool in which suction ports for cooling air for a motor are formed in an end surface of a housing of the electric power tool, striped penetrating portions are provided at positions at which the penetrating portions are not aligned with the suction ports in a tail cover mounted to the end surface, and a gap is provided between the end surface and the tail cover. With the electric power tool according to Patent Document 1, the dimension of the gap between the end surface of the housing and the tail cover is smaller than the size of crushed pieces of concrete. Thus, the crushed pieces can be prevented from passing through the gap to intrude into the housing through the suction ports for cooling air. In addition, a passage for cooling air can be formed to extend from the striped penetrating portions of the tail cover to the suction ports via the gap.
Patent Document 2 discloses an electric power tool in which a rear housing provided with a plurality of ventilation windows is screwed to the rear of a housing that houses a motor, a fan that cools the motor, etc., and filters are provided at the positions of the ventilation windows on the inner surface of the rear housing. With the electric power tool according to Patent Document 2, the filters which are permeable to air and waterproof can prevent water droplets and dust particles from intruding into the housing and cooling air for the motor can be taken into the housing through the ventilation windows. This prevents the fan housed in the housing from being damaged by foreign matter such as dust particles.